China is appealing for all sides to avoid inflaming tensions with North Korea as the United States and South Korea conclude a major naval exercise in the Yellow Sea.

But South Korean Defense Ministry officials said Wednesday they are in talks for another major exercise with the United States to take place as early as this month. South Korea is also planning its own live-fire artillery drills to take place next week.

South Korea's Yonhap news agency quoted the military command saying one of the exercises would take place near Daecheong Island, located just south of the two Koreas' disputed maritime border in the Yellow Sea. North Korea launched a deadly artillery attack on another island while South Korean forces were conducting a similar drill last week, firing into waters that both countries claim as their own.

In Beijing, the official Xinhua news agency quoted Foreign Minister Yang Jiechi saying all sides should "keep calm and exercise restraint." He is the highest ranking Chinese official to comment on the crisis.

Show of force

The joint naval exercise ending Wednesday was the largest in a series of drills staged by South Korea and the U.S. in recent months. It involved thousands of sailors, 75 aircraft and 10 warships including the nuclear-powered USS George Washington.

South Korean officials said they have not yet decided on the timing or nature of the next joint exercise. They said it would come later this month or early next year.

In New York, diplomats say China is blocking efforts at the United Nations Security Council to draw up a statement condemning North Korea for its attack on Yeonpyeong island and its development of a uranium enrichment facility.

Diplomats speaking on condition of anonymity told news services that China was unwilling to permit the use of the word "condemn" or say North Korea is in "violation" of U.N. resolutions.

Early last week, North Korea fired more than 100 artillery shells at a military garrison on the island, killing two South Korean marines and two civilians and causing widespread damage. South Korea since then has reinforced its garrison and evacuated most of the island's civilian residents.

North Korean nuclear buildup

Earlier this month, a U.S. scientist said he was shown a sophisticated uranium enrichment facility in North Korea and that he had seen more than 1,000 centrifuges in operation. Pyongyang has since claimed the facility has "thousands" of working centrifuges.

North Korea says the uranium is being enriched to power a light water reactor under construction, but foreign officials fear it could be used to make fuel for nuclear weapons.

Crisis talks

Diplomatic efforts to diffuse the tension continue on several fronts.

Foreign ministers from the United States, South Korea and Japan are to meet in Washington next week, and the issue could also come up with Russian Foreign Minister Sergei Lavrov at an international conference this week in Kazakhstan.

Choe Thae Bok, a close confidante of North Korean leader Kim Jong Il, is in Beijing for talks, and Japan said Tuesday it was sending a senior official to China to exchange views on the situation.

China is pressing for an urgent conference to be attended by China, the United States, Japan, Russia and the two Koreas. But Washington and Tokyo have shown little interest, saying North Korea must first show it is serious about giving up its nuclear programs.